A dual interface (DI or DIF) smart card may generally comprise:                an antenna module AM,        a card body CB, and        a booster antenna BA.        
The antenna module “AM” may generally comprise a “DI” RFID chip (bare, unpackaged silicon die) or chip module (a die with leadframe, carrier or the like)—either of which may be referred to as “CM”—mounted to a module tape “MT”. A module antenna MA may be disposed on the module tape MT for implementing a contactless interface. Contact pads “CP” may be disposed on the module tape MT for implementing the contact interface. The module tape MT may comprise a pattern of interconnects (conductive traces and pads) to which the chip CM and contact pads CP may be connected.
The module antenna MA may be connected, indirectly, via some of the interconnects to the chip CM, or may be directly connected to bond pads BP on the chip CM. The module antenna MA may comprise several turns of wire, such as 112 micron diameter insulated wire. Reference may be made to U.S. Pat. No. 6,378,774 (2002, Toppan), for example FIGS. 12A, B thereof.
The card body CB—which may be referred to as a substrate, or an inlay substrate—may generally comprise one or more layers of material such as Polyvinyl Chloride (PVC), Polycarbonate (PC), PET-G (Polyethylene Terephtalate Glycol-modified), Copolyester (Tritan), Teslin™, synthetic paper, paper and the like.
The card body CB may be generally rectangular, measuring approximately 54 mm×86 mm (refer to ISO/IEC 7810), having a thickness of approximately 300 μm thick. The card body CB is typically significantly (such as 20 times) larger than the antenna module AM.
The booster antenna BA may generally comprise a relatively large winding which may be referred to as a card antenna CA component (or portion) having a number of turns disposed in a peripheral area of the card body CB, and a relatively small coupler coil (or coupler antenna) CC component (or portion) having a number of turns disposed at a coupling area of the card body CB corresponding to the antenna module AM.
The card antenna CA and coupler coil CC may comprise wire mounted to (embedded in) the card body CB using an ultrasonic tool comprising a sonotrode and a capillary. See, for example U.S. Pat. Nos. 6,698,089 and 6,233,818. The wire may be non-insulated, insulated, or self-bonding wire, having an exemplary diameter in the range of approximately 50-112 μm.